CA1052169A - Variable constant volume regulator - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Air control regulators include automatically operated air curtains in which pressure and volume vary depending upon demand. A lever and fulcrum principle is used in this controller with the fulcrum position being variable. The fulcrum position can be adjusted manually or mechanically over a wide range of positions for each size of regulator and this variable location of the fulcrum varies the air flow rate through the regulator by re-positioning the flexible air curtain assembly within the regulator.

Description

~05~C~ I
BAC~:ROUND OE~ THE INVENT:tON
This invention relates to new and u~eful impro-vements in variabl~ con~tant volume regulators for use 1 :
in either single or dual duct air conditioning ~y~tems, said regulators being situated at aac~ terminal unit . in the ~ystem. ~:
.' ., ',~, ~,"',,' ,.,,~, ~ . ~: :
.. ~ ConvQntionally~ in variable volw~e sy~tems ..
both dual and ~ingle duct systems, change3 in volwme : of air result in changes in pressure in the duct system~
~ . : ~
:. 10 which effects individual units with regard to pressure! . ` ~
. ¦ and air flow.
~ . ..
.

Con~entional regulators are provided with auto~
~: matically operating flexible curtain assemblies in which the pressure and volum~ varies together depend~
. ~ ~ : 15 ing upon the demands and variations ~n the 3y~tem9 :: . ,: :-`:: '~
! ~
''': - - , `''~:
: ~ SUMMARY OF THE I~VENTION . : -; ~ In the prasent device, one of the obje~ts is :` ~ to maintain a constant air flow rate within fixed limits : ovar a wids range of air ~low rate~ regardless of the changes in pressure in the duct system and this varia~
.: bla constant vol~me d~vice constitutes an improvement over existing mathods o~ accomplishing this object and ~ ~.
accompli~hes the object to a ~ax greater degree than . here~ofore.
,, I. .-.., ~

- ~5;~9 One aspect of the invention consists o:E a variable control volume regulator for use with air supply systems which include at least one terminal unit having a volume regulator housing and a flexible curtain control assembly or the like situated in said housing and a source of control air for said regulator; the improvement com-prising in combination an actuating rod for said flex-ible curtain control assembly, operatively connected there-to, means to control the range of movement of said curtain, said means including supporting structure, a lever arm ~:
pivotally connected by one end thereof to said actuating rod, fulcrum means on said supporting structure, support-~ ing said lever arm and adjustable load means operatively: connected to the other end of said lever arm.
.` ~

The device is simple in construction, econo-mical in manufacture and otherwise well suited to the pur- `
pose for which it is designed.
'' ;::~
'. ' "'' With the foregoing in view, and other advan-, tages as will become apparent to those skilled in the art to which this invention relates as this specification pro-ceeds, the invention is herein described by reference to ;~ :
~, the accompanying drawings forming a part hereof, which in-cludes a description of the preferred typical embodiment of the principles of the present invention, in which~

, 25 DESCRIPTION OF THE DRAWINGS
.` ` .
Figure l is a typical side elevation of the .,:i : .

; - 2 - . :~
'`'~ ' ' pref~rred em~odiment which i8 a reverse acting mecha-nism ~h~wn installed on a conventional volume regula-tor hou~ing illu~trated in phantom.
:

':
~ Figure 2 is an end elevation o~ ~igure 1~ ~

: ~' ''. ' `" ;:'' ~ 5 Figure 3 is a top plan view of Figure 1~ ~

:' , Figure 4 is a fragmentary ~ide elevation in reduced scale of a direct acting a~pect of the p~e~ant ; ~:
.. , ~. .
~ in~ention. .~ ~ -:.~3 .. i -~ ~ . ::
''' ` ~ ~,- :-:
~ : In the drawings like character~ of re~erence ~ ., . -:
:~ lO;ndicate corresponding part~ in the diferent ~igure~

DETAILED DESCRIPTIoN

Proceeding therefore to describe the invention :~
.: ) . . . :
in detailt reference character lO illustrates a typical volume regulator hou~ing normally 3ituated in the tar~
15minal end o~ a duct ~y5tem (not illustrated)~

.. .. .

The hou~ing incluae~ outwardly and downwardly ~:

divergLng ~ide plateY 11 w~ich are normally perfora~ed -~ ~
: - 3 _ ~:
, i'~ : ~ . ~ . .

-- 1 0~ 9 -LS- :
as at 12 and air normally enters from the lower end 13 (with respect to the pre~ent drawings) and exits through the perforat~ on~ 12 to be di~charged in the u~ual way~
' A pair of flexible curtains 14 are normally - provided, pivoted adjacent the upper side 15 of the housing and normally being manu~actured from neoprene or sLmilar material. These can pivot outwardly or ~ ~;
inwardly in the direction of double headed arrow 16, . lO and control the volume of air passing through th~
.~ :
hou~ing, by mean~ of the pressure generated ~y thi~
air~
' , '~ ~ ' .

In the prQSQnt device~ these curtains are : normally in the opan position whereas in the direct :--:', i : , ~. :
aeting cyclo " thesQ ~urtains are normally in the ``~ ully closed position `i ~he volume regulator contxol mechani~m i~
collecti~ely designated 17. and is ituated on the ~ .
upper sidQ o~ the housing 10 (with reference to the 20 : present drawings~

~ - .
A U Dhaped mounting channel 18 i9 secured to . thiY upper ~ide ~y mean~ of nut and bolt a3~emblie , : - ~ I , .
" ' :' ,~, ':' ~os~ 9 19 and a track channel 20 i8 bolted over the upper ends of this channel 18 or ~ecured a~ by rivet~ or i any conventional means.

. . .
: '~`
An actuator channel 21 i~ ~ecured to the chan-S nel 18 intermediate the ends thereof and extendis ver-.~ ¦ tically upwardly, to carry, on one side thereof, a ful-¦ cr~n positioning actuator 22 which i9 conventional and i8 air actuated through air connection point 23, :' I , ;,'., . . ~',' ., I
: Extending at right angle9 upon the opposite ~ide of channel 21, is a limit ~top suppost 24 lying substantially paràllal with channel 18 but ispacèd ; ~ therOEfrom ae ~learly illustrated in Figure 1.

; - - ~ A pair o~ limit stop i 25 are secured to this . ~ ~ support 24 and are movable therealong 80 that they may ~:
be clamped in the des~red relationi~h~p one to the other~
~; 3i9 will hereinaftar be de9c~ibedO
: ~
'i,' ' ~
~ `!
.,,~ ~
: A main levar arm 26 is pivotally connec~ed ~y 1 ~ one end thereof aisi by pivot oonnection 27 ~ to the up~
per end of a lever arm re9ulator link 28 which in turn :~ : 20 i~ pivotally connected by the lower end thareof as in~
` : ~ 3 .., " . . ~-. .
.
: ~`

lOS;~:~f;;g - G -. dicated by reference character 29, to tha upper end of an actuating rod 30 operatively connected to the aforementioned curtains 14 or opening and closing ~ame, it being understood that vertical movement of memb~r 30 opans and clo~e9 the curtain~ 14 by means ~: o the linkage 31 ~hown in Figure 2.
.:
~' The other end of lever arm 26 i~ pivotally conn~cted as by pivot 32, to the upper end of lever arm spring link 33 to which the upper ~nd of volwme con~
:, ', trol spring 34 i5 secured as clearly illustratsd, . ~ The lower end of spring 34 i8 in turn connected to a ~ calibrating scraw 35 axtending through a ixed .bracket : ` 36 and adjusted by means o~ nuts 37 as claarly shownO
' . ,' ';: .
.
: :: . . . . , .
~ .
A pair o lever ar.ms stabilizing bar~ 38 are : - ~ 15 pivotally secured on one each side of the lever arm ~ 26 adjacent pivot point 32, and upon transverse pivot . ~ - ,~. .
: ~ or retaining shaft 39 and the other ends of the stabili~
,,~ ' ' ::
;. zing bars 38 are pi~otally secured to adjacent the oppo- ~ :
: site of channel 1~, by means of pivot or retaining : 20 shaft 40. A fulcrum assembly is provided for the lever arm 26 and takes the form o~ a fulcrum bearing ~ :
or roller 41 mounted upon a fulcrum shaft 42 which in , ;, .
.. turn is secured to a pair of fulcrum bearing and actua_ting links 43 clearly illustrated in the drawings~ An actuator l~nk ~top ~haft 44 extend~ through the other . end~ of.the link 43 and.through the distal end o~ a ::
. ~`` ' ~ , , '```,, , I
,~

1~5;~16~

plunger shaft 45 extending from the fulcrum point positioning actuator 22. This stop shaft engages the aforementioned limit stops 25 thus permitting end- :
shifting of the fulcrum bearing 41 therebetween, there-by changing the leverage action of the lever arm 26. ~ i Light tension springs 46 (Figure 1) extend between pins 47 adjacent one end of the lever arm 26 and an anchoring point within channel 18 as indicated by re-ference character 48 and act as regulator return springs. ~;~

. 10 These regulator return springs 46 ensure . the positioning of the curtains 14 in the shut-off posi-, . , ' tion under normal conditions and the lever arm stabili- : ` :
., zing bars 38 stabilize the lever arm 26 at the outboard :::
end and maintain the lever arm 26 in contact with the `~ 15 fulcrum bearing roller 41. ` .

As mentioned previously, the control mecha-nism illustated in Figures 1, 2 and 3 is for a reverse ` acting control cycle. In this control cycle, the regu- ::
: lator is normally open and provides the calibrated air flow rate. A re-positioning of the fulcrum point by means ~
` of the fulcrum bearing roller 41, causes the air flow .
; rate to decrease to some minimum value or zero if full ;:
: : ~ . .
shut-off is required. ` ~
, . . .

-''`'' `.

: , ',' `` ~ ~ ;' ~, -~I f .:~ , ' 1 : : ~ .: . - .. ~, . , - .. : : . , , HoweVer, with a di:rect acting control cycle : illustrated partially in Figure 4, the regulator is normally closec7 and there i8 no air flow. A re-posi-tioning of the fulcrum point or roller bearing 41A, in S this instance~ opens the regulator and all~ws the air flow rate to increase up to the calibrated maximum fl~w rate or maximum capacity of the regulator~
, In Figure 4 it will be noted that the actuator channel 21~ has been reversed in position and that the ; 10 fulcrum point positioning actuator 22 i9 situated on ~ the oppo8ite side to that illu9trated in ~i~urn lo :, :
. . . .
, . ~,, ,................................................................. : .
.,. ~ .
-:
-: Under these circwmstancas, the fulcrum bearing ~ . -, . ~ and actuator linXs 43 are in the form of an angulated .. . .
crank arm connected to the control sha~t 45~ as illu8i~
. ~ ~ 15 trat~d and being oonnected to the roller bearing 41~o ,'' . `` ` ' ,, ~
~ In Figure 4, similar.reference characters have :i been p~ovided but also have been provided with the ~:
., .
~ ~ su~fix "A" to dist m guish them from~he other vi~ws~ `:

. i ~ ~ .
~he rec3ulator is calibrated on a test rig in the ~actory prior to installation. It i~ calibrated r ~, , , ., ` ..
I

1~5;~
by adjusting the calibrating scraw 35 and the ad ju~t-ing nuts 37 until the specified air flow rate has been obtained and a CFM-calibration decal may then be mounted on the ~ide of the limit stop ~upport 24 and the limit stops 25 are located as required to the maximum and minimum positions. The regulator is then ~ :
checked at various inlet~ static pressures to ensure that the air flow rate is within the allowable limits .~
and ~ollowing this, tha regulator may be mounted in a ``~ ;
terminal unit or regulator housing 10 in the u~ual wayO

, ':; '` ~ : ' .~ . - , .; '` - ' . .

The control respon~e in~trument, in thi~ embo~
~ , diment, is a pneumatic thsrmostat (not illustrated) ` ~ ~ . located in the space or zona being ~upplied with air from the air conditioning ~y~temO The flow rate of :~
.:: - . . - ~
;}5 the air through the spaca is governed by the terminàl : :
unit or units each containing a variable constant volume regula~or within ~he control mechanism as .
. ; . . :
~ `: hereinbefore describedO The room thermo~tat (not : ~
: ~ , ., ,:
: ~ illustrated ) would allow air pressure to pass through to the fulcrum point po~itioning actuator 22 when an ~ :: ., ~, : ` : increase in air flow is re~uired or will bleed air`.`
: off the actuator 22 when a decea~e in air fl~w i~
requiredO Thi~ i8 with the dir~ct acting control ~;
e~uence. For a rever~e acting ~e~uence~ the abovs :~
operation is reversedO

.; .
`' ' , ` ` 1 ` `~: `

The fulcrum point positioning actuator 22 is : a pneumatic operator drivan by compressed air normally not in excess o 20 p9i. The actual operating prs#-sure range is usually 5 psi. For example, a pnaumatic operator will have an operating range o~ 5 to 10 p~i ~ or 8 to 13 p~i. Thi~ mean~ that at the lower pre~ure, the operator start~ to move and at the higher pre~suxs, the operator has completed its movementO

:
When the air prassure is removed from the . 10 pneumatic operator, there i9 an internal spring (not illuatrated) which returns the opera~or to its normal ~. -starting po~ition. ~
. , ~
' : . ' ~: '''' . . . .
: ~ With a single duct air conditioning systam : ~ supplying air to number o~ terminal units containlng the constant variable volume xegulator, the ~ollowing ~:
. ~ operation takes place. ~ .
. - . ~ - . . : ~.. -.:
..
.
.

Under ull load conditions, the terminal unit~

upply the requirad amount o~ air to the spaces or zones being con~itioned. One or more terminal units ~ , ; :
: ~ .~ 20 may be controlled by a s mgle space thermo~tat and : ~;~ under ~ull load conditions~ the maximum air ~low rate :;
, . ~: " :

. `~` ~ ' 10 _ : ;- "

will be required from any term1nal unit and the thermostat will pas8 full control air pre~sure -through to the fulcrum polnt positioning actuator 22 in the terminal unit which will po~ition the fulcrum : S point to adju~t the curtain as~embly 37 to allow the ` requirad air ~low rate~
:, .
,. ' . '''~ ~
' ''' - ' ' As the load conditions in the space are redu~
ced, the space thermo~tat will sense thi3 change and ~ ;
, will bleed air off the fulcrum point po~itioning ac~
':'`! ` 10 tuator 22 thus re-positioning the ~ulcrum point and -::
~ urthermore adju~ting the po~ition of the ~urtain as-.`! :
l sembly 14 to reduce the air flow ràte through the ~e-~ ~ ` gulator O
,"~
1, ~ I
,f ~. ~
This re-positioning of the ~ulcrum and curtain a~embly will continue in re~ponse to the ~ontrol ~ ressure from the pneumatic thermostat as the air : ~ onditioning load varies in the space~
.. . .. :
' . , , ~ ~ , .: . , .: .
,. . ~
-.: ~ It can be sesn that~ with a number of terminal : ~
.
~ ~ units going through the above cycling, a Yariation in .- ~ : ~ 20 air ~low xate and pressure in the duct 8y9tem will ~ ~ occur~
:
, ..
, .
.
, :

~-:, Where these variations in air pre3~ure occur at individual terminal units, the control mechanism will allow the curtain assem~ly 14 to react to these pres~ure variations and where the pres3ure i~ reduced, S the ~urtain as~embly 14 will open to allaw the required amount of air to paQs.

.

However~ where the pres3ure is increased, the curtain assembly will react to this increase in duct pressure and will close off to maintain the required i 10 air flow rate~ The curtain assambly 14 will re~pond ;i conti~uou~ly to thRse pressure ~ariation~ to maintain 1 a oonstant air flow rate at any position o the fulcrum, ¦ within fixed limit variations decided upon by design . ~ parameters O
~ ; ' ~

.~ ~ 15 This control mechanism can be applied to terminal units containing reheat coils whereby the ~: control mechanis~ can be made to operate in sequence :~
. with the demand ~or heat from the reheat coil~ (not illustrated)O With a reheat coil, the normal sequence : : 20 of operat~on i~ to reduce the air flow rate to ~ome ' `~
minimum value be~oxe th~ reheat coils come into ~ ;
: :
~ operationO
~; ~ ~ ~

~ - 12~
` : ' i',' ':

~ In a dual duct sy~tem, it is assumed that an - air conditioning ~ystem consists o~ two ducts, one ; duct supplying cold air and the other duct supplying warm air and connected to a numbex of tarminal unit~
- ~ .
containing the constant variable volwme regulator.
: However, as such aïr conditioning system~ are well ~ ~:
. ~ :
kn~wn, details of the ducting iB not shown in the `'~ present application.

,.~ :~
.
: ~ ~ha changing demands for air in the spaces or : . :. -.
:: 10 zones will cause pressure variations in the ducts with .. . ~ resultant variation~ in volume ~lcwing through the . .
,, .~ ,.
. . ducts~ In dual duct systems the ~low in tha cold and . ~' ' ~ ., : ~ : warm air ducts may vary over wide ranges in re~ponse ~ ~ to demand~ in the spaces or zones and there~ore may . ~:
.
. ~ I: :: 15 result in wide variations of pressure~ me ~ariable .~-constant volume regulator will respond in a similar . ~ : manner to that hereinbefors described for single duct - 1~ sy3tem~, in order to maintain a constant air flow . :~ rate despite variationq in pressure~

, ~ ~
; ~ 20: .: Since variou~ modifications can be made in my : invention as hereinabove describedO and many apparent~
: ~ ly widely diferent embodiments of same made within .
th~ spirit and 9cope of th~ ~laims without departing . ~ ~ from such spirit and scopeO it i~ intended that all . 25 matter contained in the ac~ompanying ~peci~ication ~ ~
~ shall be interpreted as illu~trative only and not in- ~ --~ : a limiting sense,

Claims

WHAT I CLAIM AS MY INVENTION IS:

(1) A variable control volume regulator for use with air supply systems which include at least one terminal unit having a volume regulator housing and a flexible curtain control assembly or the like situated in said housing and a source of control air for said regulator; the improvement comprising in combination an actuating rod for said flexible curtain control as-sembly, operatively connected thereto, means to control the range of movement of said curtain, said means in-cluding supporting structure, a lever arm pivotally connected by one end thereof to said actuating rod, fulcrum means on said supporting structure, supporting said lever arm and adjustable load means operatively connected to the other end of said lever arm.

(2) The invention according to Claim 1 in which said adjustable load means includes a tension spring extending between said other end and an anchor point, and means to adjust the tension in said spring.

(3) The invention according to Claim 1 which includes at least one stabilizing bar pivoted by one end thereof to said supporting structure and by the other end thereof to adjacent said other end of said lever arm.

(4) The invention according to Claim 2 which includes at least one stabilizing bar pivoted by one end thereof to said supporting structure and by the other end thereof to adjacent said other end of said lever arm.

(5) The invention according to Claim 1 in which said fulcrum means is adjustable within limits relative to said lever arm thereby controlling the leverage cha-racteristics of said lever arm and hence the controlling effect of said adjustable load means, upon the operation of the flexible curtain control assembly or the like within said housing.
(6) The invention according to Claim 2 in which said fulcrum means is adjustable within limits relative to said lever arm thereby controlling the leverage cha-racteristics of said lever arm and hence the controlling effect of said adjustable load means, upon the operation of the flexible curtain control assembly or the like within said housing.
(7) The invention according to Claim 3 in which said fulcrum means is adjustable within limits relative to said lever arm thereby controlling the leverage cha-racteristics of said lever arm and hence the controlling effect of said adjustable load means, upon the opera-tion of the flexible curtain control assembly or the like within said housing.
(8) The invention according to Claim 4 in which said fulcrum means is adjustable within limits relative to said lever arm thereby controlling the lever-age characteristics of said lever arm and hence the con-trolling effect of said adjustable load means, upon the operation of the flexible curtain control assembly or the like within said housing.

(9) The invention according to Claim 5 which includes means to adjust the position of said fulcrum means and further means to limit said adjustment, said last mentioned means including a pair of adjustable stop members selectively and clampably mounted for movement on said supporting structure, and means cooperating bet-ween said fulcrum means and said stop members.

(10) The invention according to Claim 6 which includes means to adjust the position of said fulcrum means and further means to limit said adjustment, said last mentioned means including a pair of adjustable stop members selectively and clampably mounted for movement on said supporting structure, and means cooperating bet-ween said fulcrum means and said stop members.
(11) The invention according to Claim 7 which includes means to adjust the position of said ful-crum means and further means to limit said adjustment, said last mentioned means including a pair of adjustable stop members selectively and clampably mounted for move-ment on said supporting structure, and means cooperating between said fulcrum means and said stop members.

(12) The invention according to Claim 8 which includes means to adjust the position of said ful-crum means and further means to limit said adjustment, said last mentioned means including a pair of adjustable stop members selectively and clampably mounted for move-ment on said supporting structure, and means cooperating between said fulcrum means and said stop members.

(13) The invention according to Claim 9 in which said fulcrum means includes a roller assembly, a roller track on said supporting structure upon which said roller assembly is mounted for endwise rolling movement therealong, an actuating link, said roller as-sembly being journalled for rotation within one end of said actuating link, said means cooperating between said fulcrum means and said stop members, being mounted on the other end of said actuating link.
(14) The invention according to Claim 10 in which said fulcrum means includes a roller assembly, a roller track on said supporting structure upon which said roller assembly is mounted for endwise rolling movement therealong, an actuating link, said roller as-sembly being journalled for rotation within one end of said actuating link, said means cooperating between said fulcrum means and said stop members, being mounted on the other end of said actuating link.

(15) The invention according to Claim 11 in which said fulcrum means includes a roller assembly, a roller track on said supporting structure upon which said roller assembly is mounted for endwise rolling movement therealong, an actuating link, said roller as-sembly being journalled for rotation within one end of said actuating link, said means cooperating between said fulcrum means and said stop members, being mounted on the other end of said actuating link.

(16) The invention according to Claim 12 in which said fulcrum means includes a roller assembly, a roller track on said supporting structure upon which said roller assembly is mounted for endwise rolling movement therealong, an actuating link, said roller as-sembly being journalled for rotation within one end of said actuating link, said means cooperating between said fulcrum means and said stop members, being mounted on the other end of said actuating link.

(17) The invention according to Claim 9 which includes control means for moving said fulcrum means between said stop members, said control means in-cluding an air actuated fulcrum point position actuator operatively connected to the source of control air.

(18) The invention according to Claims 10, 11 or 12 which includes control means for moving said fulcrum means between said stop members, said control means including an air actuated fulcrum point position actuator operatively connected to the source of control air.

(19) The invention according to Claim 13 which includes control means for moving said fulcrum means between said stop members, said control means in-cluding an air actuated fulcrum point position actuator operatively connected to the other end of said actuator link.

(20) The invention according to Claims 14, 15 or 16 which includes control means for moving said fulcrum means between said stop members, said control means including an air actuated fulcrum point position actuator operatively connected to the other end of said actuator link.